NAME¶

grpc_server - configures DNS-over-gRPC server options.

DESCRIPTION¶

The grpc_server plugin allows you to configure parameters for the DNS-over-gRPC server to fine-tune the security posture and performance of the server.

This plugin can only be used once per gRPC listener block.

SYNTAX¶

grpc_server {


    max_streams POSITIVE_INTEGER


    max_connections POSITIVE_INTEGER
}

• max_streams limits the number of concurrent gRPC streams per connection. This helps prevent unbounded streams on a single connection, exhausting server resources. The default value is 256 if not specified. Set to 0 for unbounded.
• max_connections limits the number of concurrent TCP connections to the gRPC server. The default value is 200 if not specified. Set to 0 for unbounded.

EXAMPLES¶

Set custom limits for maximum streams and connections:

grpc://.:8053 {


    tls cert.pem key.pem


    grpc_server {


        max_streams 50


        max_connections 100


    }


    whoami
}

Set values to 0 for unbounded, matching CoreDNS behaviour before v1.14.0:

grpc://.:8053 {


    tls cert.pem key.pem


    grpc_server {


        max_streams 0


        max_connections 0


    }


    whoami
}